I'm looking for performance wise. I do a lot of downloading blueray movies. I usually have a lot of windows and programs running with three of my monitor on. So I usually have my mega manager downloading, a few windows open at the same times, sometimes a movie on one screen, word and excel on another. I'm thinking about adding another 4gb of ram because when I'm downloading, average of 5-10gb at a time, I notice it's using up to 70-80% of my current 4gb of ram. That's when it really slows down my computer. There are times when my computer lag so bad where I just have to restart the computer so that it can clear up my mem and everything is running ok again. So yeah, I usually have a few internet windows open, downloading and uploading, music or movie playing, word and excel all running at the same time. Should I get two of the Caviar blk and do a raid 0 or get one Raptor 300?
Your Internet connection is much, much slower than any disk, so doing a disk upgrade isn't very likely to help you. It sounds to me like you might be out of memory and doing a lot of paging - if that's the case then a RAM upgrade is the right way to go. Remember that you can only use 4GB or more of memory if you have a 64-bit version of the OS.
In terms of WD Black vs. Velociraptor - the Black has faster transfer rates, but the Velociraptor has faster access times.
The Black will be faster at copying large files, but again this won't affect Internet downloads because they're bottlenecked by your Internet connection. It won't affect WATCHING movies either, since the data rate to view a movie at normal speed is quite slow compared to a disk drive. It WILL affect things like copying the movie files from one disk to another, though.
The Velociraptor will be faster at tasks like booting and starting up new programs.
I was thinking about adding another 4gb of mem to have a total of 8gb of mem. Should that be enough? I will probably go ahead and get me two of the blk caviar 1tb 64mb to do raid 0 on them then. Or should I buy three 640gb 32mb to go with raid 5. Which one sounds better?
RAID 0 will perform much better for writes, but will be a lot more vulnerable to disk failure than RAID 5. Make your choice based on whether you need performance or data protection. And don't forget that if your data is important then you need to make backups to external media no matter which one you choose.
Again, one has to be very careful to distinguish between TRANSFER RATES and ACCESS TIMES. The black drives are great for TRANSFER RATES, but the Velociraptors still have ACCESS TIMES that are TWICE as fast.
If you're looking to speed up a random I/O workload, the high transfer rates of the black drives really aren't going to do you much good.
I do agree that the Velociraptors are pricey, though. For someone who's looking for the best access times, it's well worth considering an SSD. For a similar cost you get a bit less storage than a Velociraptor, but a LOT faster access times.
^ I agree, I just think that Raptors are priced wrong. They do have fast access times, but not nearly fast enough to make up for what you pay for them. SSD's are really pricey, but if you care about access time, then I would take the plunge and buy an SSD before I paid for a Velociraptor. I just do not think they are a good value at all. If WD dropped the price on them by about 50%, I think they would be a decent deal.
Average price for a 300 gig V/R, $189~$200.
Average price for a 1TB Black, $99~$115.
If the Raptor was around $100 for 300gig, that I might consider.